By the end of 2020, sponsors of calendar-year single-employer retirement plans must adopt necessary and discretionary plan amendments to ensure compliance with ERISA and tax code requirements. In particular, changes to retirement plan rules under the Setting Every Community Up for Retirement Enhancement and Coronavirus Aid, Relief, and Economic Security Acts require a few actions by year-end, with some continuing into the first week of January 2021. This Client Action Bulletin looks at key areas that defined benefit and defined contribution plan sponsors should address by December 31. A year-end deadline in 2020 may also apply to some nonqualified deferred compensation plan sponsors.